biennial

adjective

bi·en·ni·al (ˌ)bī-ˈe-nē-əl

: occurring every two years

a biennial celebration

: continuing or lasting for two years

specifically, of a plant : growing vegetatively during the first year and fruiting and dying during the second

Biennial herbs flower in their second year.

biennial noun

biennially

(ˌ)bī-ˈe-nē-ə-lē

adverb

What do bimonthly and biweekly mean?: Usage Guide

Many people are puzzled about bimonthly and biweekly, which are often ambiguous because they are formed from two different senses of bi-: "occurring every two" and "occurring two times." This ambiguity has been in existence for nearly a century and a half and cannot be eliminated by the dictionary. The chief difficulty is that many users of these words assume that others know exactly what they mean, and they do not bother to make their context clear. So if you need bimonthly or biweekly, you should leave some clues in your context to the sense of bi- you mean. And if you need the meaning "twice a," you can substitute semi- for bi-. Biannual and biennial are usually differentiated.

Did you know?

Biennial conventions, celebrations, competitions, and sports events come every two years. Biennials are plants that live two years, bearing flowers and fruit only in the second year. (Carrots and sugar beets are two examples; since we're only interested in their roots, we don't wait another year to see their flower and fruit.) In contrast, semiannual means "twice a year". But no one can agree whether biweekly means "twice a week" or "every two weeks", and whether bimonthly means "twice a month" or "every two months". Maybe we should stop using both of them until we can decide.

Example Sentences

The governor explained the biennial budget proposal.

Recent Examples on the Web The National Portrait Gallery’s biennial Portrait of a Nation Award honors contemporary Americans who have made significant contributions across diverse fields.

Meilan Solly, Smithsonian Magazine, 16 Nov. 2022 Rocky Ridge Elementary School Principal Dilhani Uswatte has been chosen as one of 26 members of the National Assessment Governing Board, which oversees the National Assessment of Educational Progress, a biennial national testing effort.

Kalyn Dunkins | Kdunkins@al.com, al, 15 Nov. 2022 The biennial survey of nearly every school in the U.S. includes data on everything from test scores to staffing levels to bullying.

Chris Hacker, CBS News, 15 Nov. 2022 The biennial maternal-mortality report in Texas, due to be released last month, has been delayed until after the midterm elections.

Stephania Taladrid, The New Yorker, 10 Oct. 2022 Ryan is scheduled to speak today at the Ohio AFL-CIO’s biennial convention in Columbus.

Laura Hancock, cleveland, 27 Sep. 2022 This weekend, Disney’s biennial fan convention, the D23 Expo — a sort of state of the union for all things branded Disney — previewed some changes that might define the decade to come, including still more movie branding.

Todd Martens, Los Angeles Times, 11 Sep. 2022 These biennial plants produce seeds only in their second year, after a period of vernalization, or cold storage.

Jessica Damiano, San Diego Union-Tribune, 24 Sep. 2022 In late July the biennial meeting of the International Conference on Ephemeroptera was held virtually for the first time.

Robert O'harrow Jr., Washington Post, 19 Sep. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'biennial.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.